Responses of algae, corals and fish to the reduction of macroalgae in fished and unfished patch reefs of Glovers Reef Atoll, Belize
-
Published source details
McClanahan T.R., McField M., Huitric M. , Bergman K., Sala E., Nyström M., Nordemar I., Elfwing T. & Muthiga N.A. (2001) Responses of algae, corals and fish to the reduction of macroalgae in fished and unfished patch reefs of Glovers Reef Atoll, Belize. Coral Reefs, 19, 367-379.
Published source details McClanahan T.R., McField M., Huitric M. , Bergman K., Sala E., Nyström M., Nordemar I., Elfwing T. & Muthiga N.A. (2001) Responses of algae, corals and fish to the reduction of macroalgae in fished and unfished patch reefs of Glovers Reef Atoll, Belize. Coral Reefs, 19, 367-379.
Actions
This study is summarised as evidence for the following.
| Action | Category | |
|---|---|---|
|
Control spread of non-native/invasive/problematic plants/algae using biological, chemical and/or mechanical methods Action Link |
 |
|
|
Designate a Marine Protected Area and prohibit all types of fishing and collection Action Link |
|
-
Control spread of non-native/invasive/problematic plants/algae using biological, chemical and/or mechanical methods
A replicated, controlled, before-and-after study in 1998–1999 at 16 coral reef sites off the coast of Belize (McClanahan et al. 2001) found that removing problematic algae did not lead to an increase in stony coral or soft Gorgonian coral cover. There was no difference in stony coral cover in algae removal sites (after: 10–34%, before: 20–29%) compared to sites with no removal (after: 11–22%, before: 19–22%) and no difference for Gorgonian cover in removal (after: 2–9%, before: 7–8%) compared to non-removal sites (after: 3–7%, before: 5–7%). A year after algae removal, composition of the benthic community (including corals) had returned to its pre-removal state (data reported as graphical analysis). Overall, cover of coral declined through the course of the study (stony coral: 10% decline, Gorgonian: 3% decline). Sixteen patch reefs sites were selected (average 1,000 m2, eight in each of a wilderness and general use area). Four patches from each area had algae removed with hedge trimmers and wire brushes. Coral cover was assessed in September 1998 before algae removal, and then in October 1998 (for removal patches only), December 1998, and April and September 1999. Cover was assessed along three 10 m transects on each patch reef, and all organisms over 3 cm in size were recorded.
(Summarised by: William Morgan)
-
Designate a Marine Protected Area and prohibit all types of fishing and collection
A site comparison study in 1998–1999 in a marine reserve off the coast of Belize (McClanahan et al. 2001) found that in an area where all fishing and collection was prohibited, stony coral cover was lower and soft coral Gorgonia cover was similar compared to a general use area where some fishing was allowed. Stony coral cover was lower where fishing and collection was prohibited (10–26%) than in the general use area (15–34%), but Gorgonia cover was similar in both areas (no fishing: 3–7%, some fishing: 2–9%). Across all areas, both stony coral and Gorgonia cover declined over the course of the study (stony corals: 10% reduction, Gorgonians: 3% reduction). Sixteen patch reefs sites were selected (average 1,000 m2): eight from the area where all fishing and collection was prohibited, and eight from the area with some fishing allowed. Coral cover was assessed in September, October (half of patches) and December of 1998, and in April and September 1999 along three 10 m transects on each patch reef. All organisms over 3 cm in size were recorded. After the first sampling event, algae were removed from half of the patches.
(Summarised by: Silviu Petrovan)
